Modern Vespa

Felt like a ride on Saturday so I pulled out the 2016 GTS 300. Started just fine but has been sitting for about 4 months. Started out as normal and then scooter started acting like it was running out of gas and the engine just quit. I couldn't believe this happened because this scooter has been flawless since I bought it. Well, I got it started again and almost made it back home then it died again. Finally got it to the garage and went to work trying to figure this out. It will not stay started. I cleaned the Fuel Injector but that's it, so far. It started right up when I put it back together, so I figured that was it... well it ran for about 5 minutes then quit again and now won't start again.. Any ideas??

My first guess would be bad gas or even possibly water in the gas.

Second guess would be the fuel pump, but hopefully it's not that.

I siphoned most of the gas out and put a gallon of fresh 93 in it. Primed the fuel pump and good flow of fuel came out. Thought I might go back in and see it I didn't clean the Injector good enough.. Didn't touch the plug either. Scooter has just over 1100 mi.Just puzzled by all of this.

Check the spark plug cap is both screwed properly onto the HT lead and also clipped firmly onto the spark plug itself. A loose cap connection is often the cause of intermittent running.

Loose battery lead? I had intermittent sputtering and a few stalls, and noticed a cut in one of the battery cables. The spark plug cap was also loose.

I'll take a look at those suggestions and report the findings. Thank you..